NZ228563A

NZ228563A - Skin care composition comprising an oil phase containing a non-ionic surfactant and an aqueous phase containing a thickening agent; preparation thereof

Info

Publication number: NZ228563A
Application number: NZ228563A
Authority: NZ
Inventors: Manohar Geria Navin
Original assignee: Warner Lambert Co
Priority date: 1988-04-04
Filing date: 1989-03-31
Publication date: 1991-05-28
Also published as: AU3232989A; MX164887B; FI891590A0; KR890015727A; PT90199B; ZA892329B; PT90199A; DE68914183T2; DK159889A; DK159889D0; EP0336899B1; DE68914183D1; NO891377D0; JPH01305012A; EP0336899A2; US4992477A; NO891377L; EP0336899A3; PH25787A; ATE103486T1

Abstract

A long lasting, esthetically pleasing skin care moisturizing composition comprising (1) an oil phase comprising oil from about 30% to about 80% and a non-ionic surface active agent having an HLB number of about 7 to about 12, wherein the non-ionic surface active agent is present in an amount of about 5% to about 9%; (2) an aqueous phase comprising an aqueous thickening agent from about 0.05% to about 5% and water from about 15% to about 65% wherein the oil phase is added to the aqueous phase to form an emulsion has been developed. The method of preparation of the composition and a method of treating skin with the composition are also disclosed. m

Description

<div class="application article clearfix" id="description"> New Zealand Paient Spedficaiion for Paient Number £28563 22 85 63 NO DRAWINGS <?*)<£" Priority Date(s): Complete Specification .Filed^.V. ^1'. Class: ..ftfe.1^7?./.^.: Publication Date: . P.O. Journal. No: Patents Form No. 5 // V* O \ f/<l *•) £3 WARVW&- NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION SKIN MOISTURIZING COMPOSITION AND METHOD OF PREPARING SAME e.9/ C E » \! V' ^f'/We, WARNER-LAMBERT COMPANY/ A Corporation ^organised under the laws of the State of Delaware, USA/ of 201 Tabor Road/ Morris Plains/ New Jersey 07950, UNITED STATES OF AMERICA hereby declare the invention, for which Sy^we pray that a patent may be granted to nt^/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - 1 - (followed by page la) r o o o t" c d o u u o 10 15 This invention relates to an occlusive skin care composition and a method of preparing it. Dry skin is caused by an inadequate moisture content in the stratum corneum. The stratum corneum is a multicellular membrane of flattened, metabolically 5 active cells which forms the outer layer of skin. The membrane is dynamic, constantly renewing itself as surface cells are lost through desquamation but replaced at an equivalent rate from underlying epidermal cells. This process maintains an essentially constant number of cell and a constant thickness in the stratum corneum. The stratum corneum's water content must remain not less than approximately 10% to maintain normal skin hydration. At this moisture level, keratin (the horny skin layer) softens and attains a plastic state. This moisture level occurs in normal skin when the environment is at about 60% relative humidity. In the normal indoor environment, moisture content of the stratum corneum is about 10 to 15%. At 95% relative humidity, the stratum corneum's moisture content increases to about 65%. At low temperature and relative humidity, the outer skin layer dries out, becomes less flexible and may crack when flexed thereby increasing the rate of moisture loss. Dry skin is characterized by one or more of the following: roughness or flaking; loss of flexibility; fissures; hyperkeratosis; inflammation and pruritus. While dry skin can occur at any season, it is especially prevalent in the winter and commonly found on the forearms, back of the hands, fingers and lower legs. Other causes of dry skin include disease, prolonged detergent use, malnutrition, age and physical damage to the stratum corneum. Water is the only true plasticizer for human stratum corneum. The optimum treatment for dry skin is 20 25 30 U y CG1E5066.DOC 3/30/88 B-2 (followed by page 2)^ 18APR!99f£ vv ~ /■ 228563 2 to raise the stratum corneum1s moisture level and to reestablish its integrity. Approaches to treating dry skin include: lubricating the skin; moisturizing the skin; chemically softening the keratinous epidermal layer; treatment with anti-inflammatory medicinal compounds. A detailed discussion of the approaches for treating dry.skin is contained in Handbook of Nonprescription Drugs, eighth edition, Copyright 1986, American Pharmaceutical Assoc., Washington, D.C., Chapter 30, pages 597 to 631, the entire contents of which are hereby incorporated by reference. Moisture diffuses to the keratin layer about 50 to 100 times faster than it is lost from the skin surface. Human skin is an effective barrier against water loss. Physical damage increases transepidermal water loss. One of the primary treatments of dry skin involves the use of occlusive agents. Occlusives are hydrophobic substances that promote water retention by forming a barrier on the skin that will prevent moisture loss. The most commonly used occlusive agents include 9 petrolatum, lanolin, cocoa butter, mineral oil and silicones. Occlusives alone are not considered sufficient treatment. Patients are generally directed to soak the effected area in water for 5 to 10 minutes and then immediately apply the occlusive agent. This treatment will hydrate and then trap moisture in the skin. It is also believed that occlusives reestablish the integrity of the stratum corneum. In addition, occlusion may increase the metabolic rate of the epidermis, thereby increasing production of materials that become part of the stratum corneum. Caution must be exercised to avoid excessive hydration and maceration. The best occlusive agents are, by their very nature, oleaginous having a greasy texture and are CG1E5066.DOC 3/24/88 B-2 r 228t]G3 - 3 - difficult to spread. More esthetic oil-in-water emulsions are preferred modes for applying occlusive agents. They are less effective, however, and rely on the aid of other formulating agents to form a film on the skin after the product's water content has evaporated. While much effort has been directed to providing a highly effective, esthetically pleasing product none have been completely successful. The traditional approach has been to apply the occlusive product and produce the coating film in one step. The net result is that good esthetics are achieved at the expense of good occlusive films. Current products and methods of use have not been able to provide both a highly occlusive film and good esthetics in one product and method of use. This invention provides an occlusive skin care composition comprising, based on the total weight of the composition, (1) an oil phase comprising oil selected from animal oils, vegetable oils, mineral oils and synthetic oils, or mixtures thereof in an amount from 55% to 75% and 5% to 9% of a non-ionic surface active agent having an HLB number of 7 to 12; and (2) an aqueous phase comprising an aqueous thickening agent selected from natural gums, synthetic gums and gelling agents, or mixtures thereof in an amount of from 0.05% to 5% and water from 20% to 40%; ■ v c\\ the composition being prepared by: v 13 APR "»♦ „ / 2285G3 - 4 - forming the oil phase by dissolving the non-ionic f**) surface active agent into the oil and heating to a temperature of 60°C to 80°C to facilitate solution, forming the aqueous phase by dispersing the aqueous thickening agent in water and heating to 60°C to 80°C to facilitate dispersing, and forming a stable oil-in-water emulsion by slowly adding the oil phase to the aqueous phase with high shear mixing while maintaining a temperature of 60°C to 80°C, the oil phase being added to the aqueous phase at a slow uniform rate for at least 10 minutes. The invention also provides a method for preparing an occlusive skin care composition comprising forming an oil phase by dissolving 5% to 9% by weight of a non-ionic surface active agent having an HLB number of 7 to 12 into 55% to 75% by weight of an oil and heating to a temperature of 60°C to 80°C to facilitate solution, forming an aqueous phase by dispersing 0.05% to 5% by weight of an aqueous thickening agent, in 20% to 40% by weight of water and heating to 60°C to 80°C to facilitate dispersing, forming an emulsion by slowly adding the oil phase to the aqueous phase with high shear mixing while maintaining a temperature of 60°C to 80°C, the oil phase being added to the aqueous phase at a slow uniform rate for at least 10 . . t minutes such that a stable emulsion is formed; and > ' o recovering the skin care composition. - -» 18 APR 199)5; J 9QOr - 5 - Preferably, the oil phase is added to the aqueous phase over a period of 10 minutes to 30 minutes. The composition is directed to adding moisture to dry skin and applying a thin, long lasting occlusive film that is both effective and esthetically pleasing. The skin treating composition has the advantageous property that it increases stratum corneum flexibility by adding and sealing in moisture with a long lasting esthetically pleasing occlusive film. It has been found that the skin care composition is long lasting, esthetically pleasing and has moisturizing properties. A physically stable emulsion will not separate into layers on standing. The oil phase is formed with sufficient heating to facilitate mixing and dissolving the surface active agent in the oil. The aqueous phase is formed with sufficient heating to facilitate mixing and dispersing the aqueous thickening agent. The emulsion is formed with sufficient heating to facilitate mixing and emulsion formation. When an aqueous thickening agent is used which requires neutralization, the procedure must contain the following process step after formation of the emulsion and before recovery of the product; neutralizing the emulsion by adding with moderate mixing an effective amount of a neutralizing agent to the emulsion such that a pH of about 4.5 to about 8.2 is attained while maintaining a temperature of about 60°C to about 80°C. ' 18 APR 1991 <j o o rr4 O ,ao uo o 10 15 20 The skin care composition of the present invention provides an oil in water emulsion having high oil content from about 55% to about 75%. Compositions having such high oil content are generally physically unstable and "greasy" or "oily". The present inventive composition is physically stable. In addition, the present invention when applied to the skin produces an "oily" coating. Surprisingly the "oily" coating is readily washed off with water leaving the skin coated with a smooth "velvety", "non-oily" film of oil. The residual oil film is resistant to further washing and remains on the skin for about 8 hours. While the invention is not to be limited to theoretical considerations, it is believed that incorporation of the thickening agent into the aqueous phase physically stabilizes the emulsion providing for a long shelf life and a pharmaceutical^ acceptable appearance. It is further believed, that incorporation of a non-ionic surface active agent having an HLB number between about 7 to about 12 provides the oil in water emulsion with special properties. Emulsions of the present invention are high in oil content yet water washable. In addition, these emulsions leave a long 25 lasting velvety feeling layer of oil on the skin. The surfactant functions to aid emulsion formation and impart a water compatible property to the oil allowing an oil film to adhere to the skin surface after washing with water. 30 The oil phase of the present invention comprises an oil and a non-ionic surface active agent. Oil acts as an occlusive agent. The oils useful in the present invention are varied and may be of animal, vegetable or mineral origin. Methods of producing oils are known and 35 not a subject of the present Invention. Animal oils are derived from the organs and tissues of animals and CG1E5066.DOC 3/24/88 B-2 / *V f 18 APR I99C o 9 o sf £.£. u 0 b o 7 10 15 20 25 30 be collected through extraction, heating and/or expressing processes. Vegetable oils are usually derived from the seeds of various plants and are generally produced by extraction or pressing processes. Mineral oils are derived from petroleum and are recovered through various refining processes. Throughout the specification and claims, the term "oil" shall be defined as any oil of animal, vegetable, synthetic or mineral origin in licfuid form. The oils useful in the present invention may be food grade edible oils or nonedible oils. For example, food grade oils would be particularly useful in edible pharmaceuticals and food products. Nonedible and edible oils would be useful in topical pharmaceuticals, cosmetics, personal care products and in lubricants. Illustrative, nonlimiting examples of oils useful in the present invention include animal oils such as lanolin and the like, fatty acid esters and the marine oils: fish oil, whale oil, fish liver oil, seal oil, squalane and the like; vegetable oils such as castor oil, linseed oil, sunflower oil, soybean oil, olive oil, peanut oil, rapeseed oil, corn oil, safflower seed oil, cottonseed oil, coconut oil, palm oil, palm kernel oil, sweet almond oil, calophyllum oil, avacado oil, cerial germ oil, purcellin oil, and the like; mineral oils such as white mineral oil, parafin oil, petroleum jelly oil, petrolatum and the like. Synthetic oils such as silicone oils, dimethylpolysiloxane, cyclic silicones, methylphenylpolysiloxane, silicone-glycol copolymer and the like. Any of the oils may be used individually or in mixtures. The preferred oil is mineral oil. Oil is present from preferably from about 65% to about 75% by weight of the about 55% to about 75% and CG1E5066.DOC 3/24/88 B-2 22 8 5 6 3 8 skin care composition. The preferred oil is mineral oil. Preferably, the mineral oil will have a viscosity of about 6.0 cps to about 85.0 cps. An oil content of less than about 30% results in a composition that is too liquid, the emulsion being physically unstable. A composition with an oil content of more than about 80% does not form a stable emulsion. A surface active agent, more commonly known as a surfactant, as used herein is an organic compound consisting of two parts: a hydrophobic portion, and a hydrophilic portion which renders the compound sufficiently soluble or dispersible in water or another polar solvent. The combined hydrophobic and hydrophilic portions render the compound surface-active and thus able to concentrate at the interface between a surface active agent oil solution and another phase such as an aqueous phase. There are three types of surface active agents: (A) non-ionic, which do not dissociate, but commonly derive their hydrophilic portion from polyhydroxy or polyethoxy structures; such as polyethylene oxides, polyoxyethylene fatty acid esters; (B) anionic, where the hydrophilic portion of the molecule carries a negative charge: such as sodium lauryl sulfate, and linear alkyl sulfates, and (C) "cationic, where the hydrophilic portion of the molecule carries a positive charge: such as cetyl pryidinium chloride. Nonionic surface active agents are preferred in the present invention. Nonlimiting illustrative nonionic surfactants include: CG1E5066.DOC 3/24/88 B-2 > m "" Ml »**^ 10 15 20 25 30 35 Alkanolamides Fatty acid alkanolamides Fatty acid dialkanolamides Polyethyleneglycol derivitives Alkyl polyglycol ethers Alkyl aryl polyglycol ethers Polyglycol esters Thioethers Polyethyleneimine derivitives Alkylpolyethyleneimine f Polyethyleneimine amides rconhch2ch2oh (ethanolamides) rcon(ch2ch2oh)2 R(OCH2CH2)nOH rc6h4(och2ch2)noh rco(och2ch2)noh rs(ch2ch20)nh r(nhch2ch2)nnh2 rconh(ch2ch2nh)nh wherein n is a whole number and R is a hydrophobic chain of about 12 to about 18 carbon atoms Alkylated aryl polyether alcohol, Polyethylene glycol tert-dodecyl thioether, Fatty acid amide condensate, Aromatic polyglycol ether condensate, Secondary amide of lauric acid, Fatty acid alkanomine condensate, Sorbitan monolaurate, Sorbitan monolauratepoloxyethylene derivative, Sorbitan monooleate, CG1E5066.DOC 3/24/88 B-2 10 22 8 5 6 3 Sorbitan monooleate polyoxyethylene derivative, and Another class of non-ionic surface active agents useful in this invention are ethoxylated hydrogenated castor oils. Such surfactants are prepared by hydrogenating castor oil and treating the so-formed product with from about 10 to 200 moles of ethylene glycol. They are designated as PEG (numeral) hydrogenated castor oil in accordance with the dictionary of the Cosmetics, Toiletries and Fragrance Association, 3rd Ed. wherein the numeral following PEG indicates the degree of ethoxylation, i.e. the number of moles of ethylene oxide added. Suitable PEG hydrogenated castor oils include PEG 16, 20, 25, 30, 40, 50, 60, 80, 100 and 200. The preferred non-ionic surface active agents are polyoxyethylene fatty acid esters such as polyoxyethylene (2) stearyl ether (P0E (2) stearylether), P0E (2) oleyl ether, PPG (5) ceteth 20, POE (50) stearate, POE(20) stearyl ether, and the like. It is critical that the non-ionic surface active agent or mixture of non-ionic surface active agents have a hydrophilic - lipophilic balance number (HLB) of about 7 to about 12, preferably about 8 to about 11. The HLB is an important property of the non-ionic surface active agent since it determines the type of emulsion the surfactant tends to produce, i.e. oil in water or water in oil. A surface active agent with an HLB number less than about 7 will not form an emulsion in the present system. While a surface active agent with an HLB number greater than about 12 will form a product that does not leave an oily fraction on the skin after working as the product 35 will not bind to the skin. A surface active agent that is lipophilic in CG1E5066.DOC 3/24/88 B-2 22 85 63 10 11 character is assigned a low HLB number while a surface active agent that is hydrophilic is assigned a high number. A mixture of surface active agents will have an HLB number equivalent to a weighted average of the individual HLB numbers. For example, a surface active agent mixture of 1 part A, 2 parts Band 2 parts C, where the HLB number for A=5, B=15, and C=9 would be: HLBmix = 1/5 x 5 + 2/5 x I5 + 2/5 x 9 = 9.6 The HLB value of non-ionic surface active agents are well known in the art. A typical list of HLB values for common surface active agents is found in Cosmetics Science and Technology, second edition, Vol. 3, Balsam and Sagarin, Editors, Interscience Publishers, New York, ^ 1974 pages 583 to 597, the entire contents of which are hereby incorporated by reference. The surface active agent of the present invention may be single or a mixture. The amount of surface active agent in the present invention is about 5% to 2Q about 9%, preferable about 6% to about 8%. A surface active agent concentration greater than about 9% will produce a'very hydrophilic composition which will not spread properly having a plastic flow instead of a thixotropic flow. Surface active agent content of less 25 than about 5% will not hold an emulsion over time or at elevated temperatures and phase separation will occur. Freezing and thawing will also cause phase separation when the surface active agent content is less than about 5%. 30 The aqueous phase of the present invention comprises water and an aqueous thickening agent. Suitable thickening agents can comprise natural and synthetic gum, mixtures of gum, gelling agents and the like. Representative illustration include: 35 Natural gums: alginates, carrageenan, xanthan gum, gelatin, guar, gum arable, carob, tragacanth, CG1E5066.D0C 3/24/88 B-2 12 228563 locust bean gum, karaya, pectin, agar, and Synthetics: cellulose ethers and esters, methylcellulose, sodium carboxymethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, carbomers and carbopol Colloidal hydrated aluminum silicate: bentonite Synthetic hectorite: laponite Colloidal silica: aerosil and the like. The aqueous thickening agent is present from about 0.05% to about 5% preferably about 0.1% to about 3% and most preferably about 0.1% to about 1%. When the thickening agent is present in an amount of less than about 0.05% the emulsion is physically unstable. At amounts greater than about 5% the aqueous phase will become too thick and an emulsion will not form. The thickening agents of the present invention may swell or gel on contact with water causing the viscosity to increase by adding structure to the aqueous phase. Alternatively, the thickening agent may be of the type requiring 'neutralization with a basic composition to cause increased structure and viscosity in the aqueous phase. Examples of direct thickening agents include natural and synthetic gums, gels and cellulose derivitives. Typical thickening agents requiring neutralization include carbomers and carbopols. When'thickening agents requiring neutralizing agents are used, the neutralizing agent is added after the emulsion is formed with moderate stirring while maintaining a temperature of about 60 degrees C to about 80 degrees C. Mixing is continued until the emulsion is uniform 35 generally about 5 to about 10 minutes. Neutralizing agents useful in the present invention CG1E5066.D0C 3/24/88 B-2 22 8 5 6 3 13 include aqueous soluble basic materials. Illustrative nonlimiting examples include basic alkali metal salts and alkaline earth metal salts such as hydroxides and carbonates and basic amine compounds such as triethanolamine, isopropylamine and the like. The ratio of thickening agent to neutralizing agent is about 1:4 to about 1:10. The pH of the emulsion after neutralization is about 4.5 to about 8.2. Water is present in an amount of about 15% to about 65%, preferably from about 20% to about 40% and most preferably from about 25% to about 35%. The present invention may further include ingredients such as colorants, preservatives, antioxidants, medicaments, moisturizers, sunscreen agents, germicides, deodorants, antiperspirants, healing agents, solvents, humectants, thickeners for the oily phase, emollients, buffers, fragrances, flavors and abrasives. These ingredients are genrally added after the emulsion is formed. The present invention is further illustrated by the following'examples. All parts and percentages in the examples and throughout the specification and claims are by weight of the final composition unless otherwise indicated. CG1E5066.DOC 3/24/88 B-2 22 8 5 6 3 14 EXAMPLE 1 (Inventive Run A and Comparative Run 1) This Example demonstrates the effect of rate of addition of the oil phase to the aqueous phase on formation of the skin care composition. Formula A 1 Ingredients (% w/w) 1% w/w) Deionized Water 20.15 20.15 Methyl paraben 0.20 0.20 Propyl paraben 0.10 0.10 Imidazolidinyl Urea 0.30 0.30 Carbomer 940 0.15 0.15 Triethanolamine 98% 1.50 1.50 POE (2) Stearyl Ether 3.00 3.00 Mineral Oil 70.00 70.00 PPG-5-ceteth-20 0.10 0.10 POE (20) Stearyl Ether 4.00 4.00 Fragrance 0.50 0.50 TOTAL 100.00 100.00 HLB Number 10.7 10.7 Procedure: the water phase was prepared by adding the methylparaben, propylparaben and imidazolidinyl urea (preservative) and carbomer 940 (thickener) to the water with mixing to disperse and then raising the water temperature to about 75 to 80 degrees C. with continued mixing. The oil phase was prepared by adding the surface active agents PPG-5-CETETH-20, POE(2) stearyl ether and POE (20) stearyl ether to the oil with mixing then raising the temperature to about 75 to 80 degrees C. CG1E5066.DOC 3/24/88 B-2 22 8 5 63 15 The emulsion is then formed by adding the oil phase to the water phase and mixing at high shear. In inventive Run A, the oil phase is added to the water phase at about 5ml/minute equal to about 15 minutes. For comparative Run 1, the oil phase is added to the water phase at about 15ml/minute equal to about 5 minutes. The neutralizing agent is then added to the emulsion with mixing continuing until the product is uniform. Run A forms a smooth creamy emulsion that is physically stable. The product is acceptable. Run 1 forms a physically unstable product. Oil separates from the emulsion, the product deflocculates and is unacceptable. CG1E5066.D0C 3/24/88 B-2 20 25 22 85 63 16 EXAMPLE 2 (Comparative Runs 2 and 3) This Example demonstrates the effect of surface active agents having an HLB number less than 7 and 5 greater than 12. The compositions of this example are prepared by the process of Example 1 Run A. Run 2 has an HLB number of 16.2. Run 3 has an HLB number of 5.1. Formula 2 3 10 Ingredients (% w/w) (% w/w) Deionized water 20.15 20.15 Methyl paraben 0.20 0.20 Proply paraben 0.10 0.10 Imidazolidinyl Urea 0.30 0.30 Carboxyvinyl Polymer 940 0.15 0.15 Triethanolamine 98% 1.50 1.50 POE (2) Stearyl ether 3.00 POE (50) Stearate - 3.00 Mineral Oil 70.00 70.00 PPG-5-ceteth-20 0.10 0.10 POE (2) Oleylether 4.00 POE (20) Stearyl ether - 4.00 Fragrance 0.50 0.50 Total 100.00 100.00 HLB Number 16.2 5.1 30 Both Runs *2 and 3 produce products that are physically unstable. The oil separates out of the emulsion. 35 CG1E5066.DOC 3/24/88 B-2 17 22 8 5 6 3 Calculation of HLB % of Total Surface Active Agent Frac-tion-HLB al Number HLB 10 15 Run 3 POE (2) Stearyl ether 42.3 5.0 2.1 POE (2) Oleyl ether 56.3 4.9 2.8 PPG (5) Ceteth 20 1.4 15.0 0.2 Run 3 Total HLB Number 5.1 Run 2 POE (50) Stearate 42.3 17.9 7.6 POE (20) Stearyl ether 56.3 15.0 8.4 PPG (5) Ceteth 20 1.4 15.0 0.2 Run 2 Total HLB Number 16.2 20 w1 25 30 35 CG1E5066.DOC 3/24/88 B-2 </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 22 8 5 6 J 18 EXAMPLE 3 (Inventive Runs B and C) This Example demonstrates the effect of oil content on the emulsion. The compositions of this Example are prepared by the process of Example 1 Run A. B C Formula Ingredients % w/w % w/w Deionized Water 15.00 60.15 Methyl paraben 0.20 0.20 Propyl paraben 0.10 0.10 Imidazolidinyl Urea 0.30 0.30 Carboxyvinyl Polymer 940 0.15 0.15 Triethanolamine 98% 1.50 1.50 POE (2) Stearyl Ether 3.00 3.00 Mineral Oil 75.15 30.00 PPG-5-ceteth-20 0.10 0.10 POE (20) Stearyl Ether 4.00 4.00 Fragrance 0.50 0.50 100.00 100.00 HLB Number 10.7 10.7 Run B product is stringy and pituitive, emulsion is acceptable but marginal. Run C product is a thin liquid, emulsion is acceptable but marginal. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not be regarded as a departure from the spirit of scope of the invention and all such modifications are intended to be included within the scope of the claims. CG1E5066.D0C 3/24/88 B-2 - 19 - 2285 G 3 WHAT WE CLAIM IS;

1. An occlusive skin care composition comprising, based on the total weight of the composition, (1) an oil phase comprising oil selected from animal oils, vegetable oils, mineral oils and synthetic oils, or mixtures thereof in an amount from 55% to 75% and 5% to 9% of a non-ionic surface active agent having an HLB number of 7 to 12; and (2) an aqueous phase comprising an aqueous thickening agent selected from natural gums, synthetic gums and gelling agents, or mixtures thereof in an amount of from 0.05% to 5% and water from 20% to 40%; the composition being prepared by: forming the oil phase by dissolving the non-ionic surface active agent into the oil and heating to a temperature of 60°C to 80°C to facilitate solution, forming the aqueous phase by dispersing the aqueous thickening agent in water and heating to 60°C to 80°C to facilitate dispersing, and forming a stable oil-in-water emulsion by slowly adding the oil phase to the aqueous phase with high shear mixing while maintaining a temperature of 60°C to 80°C, the oil phase being added to the aqueous phase at a slow uniform rate for at least 10 minutes.

2. A skin care composition of claim 1 in which the aqueous phase also comprises a neutralising agent.

3. The composition of claim 2 wherein the <- A. / neutralizing agent is selected from basic alkali metal , v. " o salts, basic alkaline earth metal salts and basic amine compounds, or mixtures thereof. 18APR199I

4. The composition of claim 2 wherein the neutralizing agent is selected from alkali metal and alkaline earth metal hydroxides and carbonates, triethanol amine, and isopropylamine, or mixtures thereof.

5. The composition of any one of claims 1 to 4 wherein the animal oil is selected from lanolin, fatty acid 9 9 orrQ esters, fish oil, whale oil, fish liver oil, seal oil and sgualane or mixtures thereof.

6. The composition of any one of claims 1 to 5 wherein the vegetable oil is selected from castor oil, linseed oil, sunflower oil, soybean oil, olive oil, peanut oil, rapeseed oil, corn oil, safflower seed oil, cottonseed oil, coconut oil, palm oil, palm kernel oil, sweet almond oil, calophyllum oil, avocado oil, cereal germ oil and purcellin oil, or mixtures thereof.

7. The composition of any one of claims 1 to 6 wherein the mineral oil is selected from white mineral oil, paraffin oil, petroleum jelly oil and petrolatum, or mixtures thereof.

8. The composition of any one of claims 1 to 7 wherein the synthetic oil is selected from silicone oils, dimethylpolysiloxane, cyclic silicones, methylphenylpolysiloxane, and silicone-glycol copolymer, or mixtures thereof.

9. The composition of any one of claims 1 to 8 wherein the non-ionic surface active agent is selected from alkanolamides, polyoxyethylenes, polyoxyethylene fatty acid esters, polyethyleneglycol derivatives, polyethyleneimine derivatives, and ethoxylated hydrogenated castor oils.

10. The composition of any one of claims 1 to 8 wherein the non-ionic surface active agent is selected from the group consisting of polyoxyethylene (2) stearyl ether, polyoxyethylene (2) oleyl ether, polypropyleneglycol (5) ceteth 20, polyoxyethylene (5) stearate and polyoxyethylene (20) stearyl ether, or mixtures thereof.

11. The composition of any one of claims 1 to 10 1 8 APR 1991 wherein the natural gum is selected from alginates, carrageenan, xanthan gum, gelatin, guar, gum arabic, carobt,?jM tragacanth, locust bean gum, karaya, pectin and agar, or mixtures thereof.

12. The composition of any one of claims 1 to 11 wherein the synthetic gum is selected from cellulose ethers and esters, methylcellulose, sodium carboxymethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, carbomers and carbopol, or mixtures thereof. 9 9 0 r- o >C. C U u v.) i J

13. The composition of any one of claims 1 to 12 wherein the gelling agent is selected from colloidal hydrated aluminum silicate, bentonite, synthetic hectorite, laponite and colloidal silica, or mixtures thereof.

14. A composition according to claim 1 and substantially as described in this specification with reference to example 1 or example 3.

15. A method for preparing an occulusive skin care composition comprising forming an oil phase by dissolving 5% to 9% by weight of a non-ionic surface active agent having an HLB number of 7 to 12 into 55% to 75% by weight of an oil and heating to a temperature of 60cC to 80°C to facilitate solution, forming an aqueous phase by dispersing 0.05% to 5% by weight of an aqueous thickening agent, in 20% to 40% by weight of water and heating to 60°C to 80°C to facilitate dispersing, forming an emulsion by slowly adding the oil phase to the aqueous phase with high shear mixing while maintaining a temperature of 60°C to 80°C, the oil phase being added to the aqueous phase at a slow uniform rate for at least 10 minutes such that a stable emulsion is formed; and recovering the skin care composition.

16. A method according to claim 15 in which a neutralizing agent is added to the emulsion.

17. The method of claim 16 wherein the neutralizing agent is selected from basic alkali metal, alkaline earth metal salts and basic amine compounds, or mixtures thereof.

18. The method of claim 16 wherein the neutralizing agent is selected from alkali metal and alkaline earth metal hydroxides and carbonates, triethanolamine, and isopropylamine, or mixtures thereof.

19. The method of any one of claims 15 to 18 wherein the oil is selected from animal oils, vegetable oils, mineral oils, and synthetic oils, or mixtures thereof.

20. The method of claim 19 wherein the animal oil is. ___ selected from lanolin, fatty acid esters, fish oil, whale^ E w oil, fish liver oil, seal oil and squalane or mixtures, ^ thereof. 18 APR 1991 i - 22 - 9 9 s t'' 'I C. C. U O U o

21. The method of claim 19 or claim 20 wherein the vegetable oil is selected from castor oil, linseed oil, sunflower oil, soybean oil, olive oil, peanut oil, rapeseed oil, corn oil, safflower seed oil, cottonseed oil, coconut oil, palm oil, palm kernel oil, sweet almond oil, calophyllum oil, avocado oil, cereal germ oil and purcellin oil, or mixtures thereof.

22. The method of any one of claims 19 to 21 wherein the mineral oil is selected from white mineral oil, paraffin oil, petroleum jelly oil and petrolatum, or mixtures thereof.

23. The method of any one of claims 19 to 22 wherein the synthetic oil is selected from silicone oils, dimethylpolysiloxane, cyclic silicones, methylphenylpolysiloxane and silicone-glycol copolymer, or mixtures thereof.

24. The method of any one of claims 15 to 23 wherein the non-ionic surface active agent is selected from alkanolamides, polyoxyethylenes, polyoxyethylene fatty acid esters, polyethyleneglycol derivatives, polyethyleneimine derivatives, and ethoxylated hydrogenated castor oils.

25. The method of any one of claims 15 to 23 wherein the non-ionic surface active agent is selected from polyoxyethylene (2) stearyl ether, polyoxyethylene (2) oleyl ether, polypropyleneglycol (5) ceteth 20, polyoxyethylene (5) stearate and polyoxyethylene (20) stearyl ether or mixtures thereof.

26. The method of any one of claims 15 to 25 wherein the aqueous thickening agent is selected from natural gums, synthetic gums and gelling agents, or mixtures thereof.

27. The method of claim 26 wherein the natural gum is selected from alginates, carrageenan, xanthan gum, gelatin, guar, gum arabic, carob, tragacanth, locust bean gum, karaya, pectin and agar, or mixtures thereof.

28. The method of claim 26 or claim 27 wherein the synthetic gum is selected from cellulose ethers and esters, methylcellulose, sodium carboxymethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, carbonic^ and carbopol, or mixtures thereof. \ 18 APR 1991m - 23 - 2285G3

29. The method of any one of claims 2 6 to 28 wherein the gelling agent is selected from colloidal hydrated aluminum silicate, bentonite, synthetic hectorite, laponite, and colloidal silica, or mixtures thereof.

30. The method according to claim 15 and substantially as described in this specification with reference to example 1 or example 3.

31. A skin care composition whenever made by a process according to any one of claims 15 to 30. \ r. N >-s > ^ O \ '• i *"» " ' • S 18APR1991S; \ / •V J warner-lambert company .X\; 1 /] \ b^ Itih^ir attorneys BALDWIN, SON & CAREY </div>